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Öğe Anaplastic astroblastoma of childhood: aggressive behavior(Springer, 2009) Kantar, M.; Ertan, Y.; Turhan, T.; Kitis, O.; Anacak, Y.; Akalin, T.; Ersahin, Y.; Cetingul, N.Objective Astroblastoma is an unusual brain tumor in childhood. Tumor usually arises from cerebral hemispheres. This large tumor is well-demarcated, lobulated, solid or cystic, and therefore, may resemble glioblastoma. Histopathologically, there are two types of astroblastoma: well-differentiated (low-grade) or anaplastic (high-grade). In low-grade astroblastoma, treatment of choice is complete excision. This type of tumor usually does not recur. However, anaplastic tumors can recur despite surgery, radiation, and chemotherapy and may be problematic for clinician. Case Report A 7-year-old female patient presented with an acute onset of vomiting and seizure. Magnetic resonance imaging study revealed a large mass in the left parietooccipital region. She underwent total excision of the tumor. Histopathologically, the tumor was an anaplastic astroblastoma. Her adjuvant treatment was planned to consist of radiation therapy and cisplatin-based chemotherapy. However, the tumor recurred early in the course, and she died 18 months after diagnosis. Conclusion High-grade astroblastomas behave like glioblastoma, as emphasized in this case report. Local control of this type of tumor seems difficult despite surgery, radiation therapy, and cisplatin-based chemotherapy.Öğe Anaplastic astroblastoma of childhood: aggressive behavior(Springer, 2009) Kantar, M.; Ertan, Y.; Turhan, T.; Kitis, O.; Anacak, Y.; Akalin, T.; Ersahin, Y.; Cetingul, N.Objective Astroblastoma is an unusual brain tumor in childhood. Tumor usually arises from cerebral hemispheres. This large tumor is well-demarcated, lobulated, solid or cystic, and therefore, may resemble glioblastoma. Histopathologically, there are two types of astroblastoma: well-differentiated (low-grade) or anaplastic (high-grade). In low-grade astroblastoma, treatment of choice is complete excision. This type of tumor usually does not recur. However, anaplastic tumors can recur despite surgery, radiation, and chemotherapy and may be problematic for clinician. Case Report A 7-year-old female patient presented with an acute onset of vomiting and seizure. Magnetic resonance imaging study revealed a large mass in the left parietooccipital region. She underwent total excision of the tumor. Histopathologically, the tumor was an anaplastic astroblastoma. Her adjuvant treatment was planned to consist of radiation therapy and cisplatin-based chemotherapy. However, the tumor recurred early in the course, and she died 18 months after diagnosis. Conclusion High-grade astroblastomas behave like glioblastoma, as emphasized in this case report. Local control of this type of tumor seems difficult despite surgery, radiation therapy, and cisplatin-based chemotherapy.Öğe Automated classification of MR images for recognising Alzheimer's disease in living patients(Elsevier Science Bv, 2010) Simsek, F.; Polat, F.; Demirel, O.; Kitis, O.; Haznedaroglus, D.; Eker, C.; Kumral, E.; Gonul, A. S.Öğe Brain parenchymal fraction is significantly reduced in early multiple sclerosis: a quantitative MRI study(Wiley, 2015) Ucar, C. Atac; Yuceyar, A. N.; Kitis, O.; Ekmekci, O.; Kocaman, A. SagduyuÖğe Brain parenchymal fraction is significantly reduced in early multiple sclerosis: a quantitative MRI study(Wiley, 2015) Ucar, C. Atac; Yuceyar, A. N.; Kitis, O.; Ekmekci, O.; Kocaman, A. SagduyuÖğe Brain parenchymal fraction is significantly reduced in early multiple sclerosis: a quantitative MRI study(Wiley, 2015) Ucar, C. Atac; Yuceyar, A. N.; Kitis, O.; Ekmekci, O.; Kocaman, A. SagduyuÖğe Brain regions associated with the risk and resilience for bipolar I disorder: a voxel based MRI study(Elsevier Science Bv, 2012) Simsek, F.; Eker, M. C.; Kitis, O.; Haznedaroglu, D. I.; Cinar, C.; Bilgi, M. M.; Isikli, S.; Coburn, K.; Gonul, A. S.Öğe Brucellar spondylodiscitis: magnetic resonance imaging features with conventional sequences and diffusion-weighted imaging(Springer, 2010) Oztekin, O.; Calli, C.; Adibelli, Z.; Kitis, O.; Eren, C.; Altinok, T.In this retrospective study, we evaluated the contribution and role of diffusion-weighted imaging (DWI) in differentiating acute and chronic forms of brucellar spondylodiscitis. We also describe the characteristics and some indistinguishable features of brucellar spondylodiscitis on magnetic resonance imaging (MRI) to emphasise the importance and limitations of MRI. MRI examinations of 25 patients with brucellar spondylodiscitis were retrospectively reviewed and analysed by two experienced radiologists. Signal and morphological changes were assessed. The imaging characteristics of acute and chronic forms of spondylodiscitis were compared. Both discriminative imaging findings of brucellar spondylodiscitis and some uncommon findings were interpreted. Of 25 patients with spinal brucellosis, eight had thoracic, ten had lumbar, five had both thoracic and lumbar and two had both lumbar and sacral vertebral involvement. We detected posterior longitudinal ligament elevation in 11 patients, epidural abscess formation in 11 and paravertebral abscess formation in nine. Ten patients had cord compression and eight had root compression. Three patients had facet-joint involvement, and one had erector spinae muscle involvement. Eight patients (32%) were in the acute stage, six (24%) in the subacute stage and 11 (44%) in the chronic stage. Vertebral bodies, vertebral end plates and intervertebral disc spaces were hypointense and hyperintense in the acute stage, whereas they were hypointense and heterogeneous in the subacute and chronic stages on T1- and T2-weighted images, respectively. In the acute stage on the DWI series, vertebral bodies, end plates and discs were all hyperintense but hypointense in the chronic stage. Although conventional MRI has several advantages over other imaging modalities and is very useful in the differential diagnosis between brucellar spondylodiscitis and other spinal pathologies, it has some difficulties in discriminating acute and chronic forms of spondylodiscitis. DWI is a sensitive, fast sequence that has the potential for differentiating acute and chronic forms of spondylodiscitis, which makes it crucial in spinal imaging.Öğe A CASE OF MACROCEPHALY-CAPILLARY MALFORMATION SYNDROME PRESENTING WITH HOT WATER EPILEPSY(Medecine Et Hygiene, 2015) Yilmaz, S.; Tekin, H.; Kitis, O.; Serdaroglu, G.; Tekgul, H.; Gokben, S.Öğe Cerebral cortical and deep venous thrombosis without sinus thrombosis: clinical MRI correlates(Blackwell Publishing, 2006) Sagduyu, A.; Sirin, H.; Mulayim, S.; Bademkiran, F.; Yunten, N.; Kitis, O.; Calli, C.; Dalbasti, T.; Kumral, E.Background - Cortical and/or deep vein thrombosis (CDVT) without dural sinus involvement is uncommon and presents diagnostic difficulty for many reasons. Our aim is to determine the relationship between magnetic resonance imaging (MRI) findings and clinical findings in patients with CDVT. Methods - Forty-six patients with venous stroke proved on MRI included in our Registry, corresponding to 0.1% of 4650 patients with stroke, were studied. Magnetic resonance angiography (MRA) was performed in all patients, and 18 of them had follow-up MRA. Outcome was evaluated by using the Glasgow Outcome Scale at the time of discharge and during follow-up. Results - Thirty-two patients presented cortical venous stroke; 21 of them had involvement of the dorsomedial venous system, six had a defect in the posteroinferior venous group, and five had a defect in the anteroinferior venous group. Thirteen patients presented simultaneous involvement of the superficial and deep venous system; seven with a defect in the parietal and internal cerebral veins (three with involvement of vein of Gallen), four with a defect in the temporooccipital (vein of Labbe) and basal vein of Rosenthal, two with a deficit in the anterior frontotemporal and uncal-pterygoid venous system. One patient had deep venous thrombosis primarily localized to the thalami bilaterally and the basal ganglia on the right because of occlusion of the thalamostriate veins. The main presenting symptoms of CDVT were headache, focal neurologic signs, partial complex or secondary generalized seizures, and consciousness disturbances in those with deep venous thrombosis, presented alone or in combination at onset. CDVT was more than twofold more frequent in women than in men. Pregnancy, puerperium, oral contraceptive use, and infections were the most common predisposing factors. Conclusions - Computerized tomography, conventional MRI and diffusion-weighted imaging showing ischemic and/or hemorrhagic lesion that does not follow the boundary of classical arterial boundaries without signs of sinus thrombosis, and partial or generalized seizures followed by focal neurologic signs may predict CDVT. The outcome of patients with cortical venous stroke was good, but not in those with cortical plus deep venous infarction.Öğe The clinical spectrum of intracerebral hematoma, hemorrhagic infarct, non-hemorrhagic infarct, and non-lesional venous stroke in patients with cerebral sinus-venous thrombosis(Wiley, 2012) Kumral, E.; Polat, F.; Uzunkopru, C.; Calli, C.; Kitis, O.Background and purpose: The clinical spectrum of different neuroradiological features of cerebral sinusvenous thrombosis (CSVT) varies considerably. We sought the relationship between different neuroradiological aspects and clinical presentations in these patients. Methods: The diagnosis of cerebral sinus-venous thrombosis has been confirmed by conventional angiography, MRI combined with MR venography following established diagnostic criteria. We analyzed clinical data, symptoms and signs, imaging findings, location and extent of the thrombus, and parenchymal lesions, retrospectively. Results: There were 220 consecutive patients with cerebral sinus-venous thrombosis; 98 (45%) had non-lesional sinus-venous thrombosis (NL CSVT), 51 (23%) had nonhemorrhagic infarct (NHI), 45 (20%) had hemorrhagic infarct (HI), and 26 (12%) had intracerebral hemorrhage (ICH). In patients with hemorrhagic lesion (HI + ICH), advanced age, headache (99%), behavioral disturbances (55%), consciousness disturbances (35%), seizures (41%), and language deficits (42%) were significantly higher than the other patients (NL + NHI) (P < 0.001). High blood pressure at admission, puerperium, sigmoid and straight sinus thrombosis, multiple sinus and vein involvement were more frequent in patients with hemorrhagic lesion than those with nonhemorrhagic lesion. Patients with hemorrhagic lesion were more dependent or died (32%) than the other patients (12%) (P < 0.001), and most of the patients with NL and NHI had no disability compared with the other patients at the 3 month of followup (96% and 65%; P < 0.001). Conclusion: Headache, convulsion, behavioral disorder, seizures, and speech disorders were the most frequent clinical symptoms of patients with hemorrhagic CSVT. Specific risk factors, including pregnancy/puerberium, early and extended thrombosis of large sinus, and presence of high blood pressure at admission, are associated with hemorrhagic lesion and unfavorable outcome.Öğe Diagnosis of bipolar disease using correlation-based feature selection with different classification methods(Institute of Electrical and Electronics Engineers Inc., 2019) Cigdem, O.; Sulucay, A.; Yilmaz, A.; Oguz, K.; Demirel, H.; Kitis, O.; Unay, D.Three-Dimensional Magnetic Resonance Imaging (3D-MRI) and Computer-Aided Detection (CAD) have been widely studied in the detection of bipolar disorder (BD). In this study, the structural alterations at the grey matter (GM) and white matter (WM) of BD subjects versus healthy controls (HCs) have been compared using Voxel-Based Morphometry (VBM). In order to obtain 3D GM and WM masks, the two sample ttest method and total intracranial volumes of BD and HC as a covariate have been utilized. In addition to analyzing effects of GM and WM tissue maps separately in the detection of BD, impacts of both GM and WM ones are studied by concatenating them in a matrix. The correlation-based feature selection (CFS) feature ranking method is applied to the obtained 3D masks to rank the features, the number of selected top-ranked features are determined using a Fisher criterion (FC) approach, and different classification algorithms are used to classify BD apart from HCs. In this study, 26 BDs and 38 HCs data are used. The experimental results indicate that the classification accuracy of Naive Bayes outperforms the other four classification algorithms used in this study. Additionally, concatenation of GM and WM tissue maps enhances the classification performances of using GM-only and WM-only ones. The classification accuracies obtained for GM, WM, and their concatenation are 72.92%, 78.33%, and 80.00% respectively. © 2019 IEEE.Öğe Dysembryoplastic Neuroepithelial Tumour of Childhood: EGE University Experience(Wiley-Blackwell, 2016) Sahin, A.; Kantar, M.; Turhan, T.; Akalin, T.; Kitis, O.; Bolat, E.; Eraslan, C.; Ertan, Y.; Serdaroglu, G.; Cetingul, N.; Anacak, Y.; Mutluer, S.Öğe Identification of axonal involvement in Hallervorden-Spatz disease with magnetic resonance spectroscopy(Masson Editeur, 2006) Kitis, O.; Tekgul, H.; Erdemir, G.; Polat, M.; Serdaroglu, G.; Tosun, A.; Coker, M.; Gokben, S.Hallervorden-Spatz disease is a neurodegenerative disorder associated with cysteine-iron complex accumulation typically seen as bilateral symmetrical hypointense signal changes in the medial globus pallidus on magnetic resonance imaging. We used magnetic resonance spectroscopy to identify and quantify neuronal damage in two siblings with Hallervorden-Spatz disease. The first patient presenting with a rapidly progressive extrapyramidal syndrome had markedly decreased Nacetylaspartate (NAA) to creatinine (Cr) ratios in the globus pallidi and the periatrial white matter. He also had increased myoinositol (ml) to creatinine (Cr) ratios implying glial proliferation in the affected regions. However the second patient who had the initial presentation of disease had normal NAA/Cr and ml/Cr ratios. These findings indicate that the quantification of NAA:Cr and ml:Cr ratios might be used to predict the extent of neuronal axonal loss and glial proliferation in patients with Hallervorden-Spatz disease respectively.Öğe Neural activation during cognitive reappraisal in girls at high risk for depression(Pergamon-Elsevier Science Ltd, 2017) Simsek, F.; Oguz, K.; Kitis, O.; Akan, S. T.; Kempton, M. J.; Gonul, A. S.Objective: Although emotion dysregulation, one of the core features of depression, has long been thought to be a vulnerability factor for major depressive disorder (MDD), surprisingly few functional magnetic resonance imaging (fMRI) studies have investigated neural correlates of emotion regulation strategies in unaffected high risk individuals. Method: Sixteen high risk (RSK) young women and fifteen matched low risk controls (CU) were scanned using fMRI while performing an emotion regulation task. During this task, participants were instructed to reappraise their negative emotions elicited by International Affective Picture System images (TAPS). In addition, Difficulties in Emotion Regulation Strategies Scale (DERS) was used to assess participants' emotion dysregulation levels. Results: Both RSK and CTL individuals show increased amygdala activation in response to negative emotional stimuli, however no difference was found between groups in using cognitive reappraisal strategies and functions of brain regions implicated in cognitive reappraisal. Interestingly, our psychometric test results indicate that high risk individuals are characterised by lower perceived emotional clarity (EC). Conclusion: Results of the current study suggest depression vulnerability may not be linked to the effectiveness of cognitive reappraisal. Alternatively, lower EC may be a vulnerability factor for depression.Öğe Pituitary gland volumes in major depressive disorder patients(Elsevier Science Bv, 2007) Eker, O. Donat; Ovali, G. Yilmaz; Eker, M. C.; Kitis, O.; Ozan, E.; Akdeniz, F.; Vahip, S.; Gonul, A. S.Öğe Serum BDNF levels correlate with hippocampal volumes in first episode, medication-free depressed patients(Elsevier Science Bv, 2009) Eker, M.; Kitis, O.; Taneil, F.; Eker, O. D.; Ozan, E.; Yucel, K.; Coburn, K.; Gonul, A. S.Öğe Serum BDNF levels correlate with hippocampal volumes in first episode, medication-free depressed patients(Elsevier Science Bv, 2009) Eker, M.; Kitis, O.; Taneil, F.; Eker, O. D.; Ozan, E.; Yucel, K.; Coburn, K.; Gonul, A. S.